A controversial way to solve violent crimes

Idaho police recently arrested Bryan Kohberger on suspicion of murdering four college students in November.

The tech used to apprehend him is a controversial one that involves public DNA databases, per Business Insider.

How it works

Online tools, like GEDmatch, compare DNA test results from companies like 23andMe and Ancestry. Users download their DNA data file, upload it to GEDmatch, and potentially find relatives around the world.

But cops use GEDmatch, too:

• In 2018, police used GEDmatch to arrest Joseph James DeAngelo, AKA the Golden State Killer, after matching crime scene DNA to his distant relative.
• In 2019, GEDmatch was acquired by Verogen, a forensic firm that works with law enforcement. Now, users who opt to share DNA do so with investigators.

It’s a complicated issue

Some advocates tout the tech’s ability to solve cold cases and exonerate the innocent.

Others argue it’s a violation of privacy that must be regulated (e.g., restricted to only certain violent crimes). Just because you opt to share your DNA doesn’t mean your relatives do. Also:

• DNA testing isn’t infallible, and has led to wrongful convictions due to human error, contamination, secondary transfer, and other factors.

Podcast: NHPR’s Bear Brook explores the first cold case solved using genetic genealogy.